Prefill form with existing card details

[jflinter]

This issue was migrated from stripe-ios: stripe/stripe-ios#17

[cannyboy]

this would be useful in conjunction with https://github.com/card-io/card.io-iOS-SDK

[cannyboy]

I just wanted to fill in the card number from the number returned from card-io. Not the CVC or expiry.

I could do this separating a card number string into an array of single character NSStrings, and iterating through the array, and pasting the string up to that point into the cardNumberField

UIPasteboard *pb = [UIPasteboard generalPasteboard];
NSString *originalPasteboard = pb.string;
NSMutableArray *numberArray = [NSMutableArray array];
NSString *str = info.cardNumber;
for (int i = 0; i < [str length]; i++) {
    NSString *ch = [str substringWithRange:NSMakeRange(i, 1)];
    [numberArray addObject:ch];
}
[cell.paymentView.cardNumberField becomeFirstResponder];
cell.paymentView.cardNumberField.text = @"";
for (int i = 0; i < [numberArray count]; i++) {
    float f = (float)i * 0.02;
    NSString *number = [numberArray objectAtIndex:i];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        NSMutableString *newString = [cell.paymentView.cardNumberField.text mutableCopy];
        [newString appendString:number];
        pb.string = number;
        [cell.paymentView.cardNumberField paste:self];
        pb.string = @"";
        if (i == (numberArray.count-1)) pb.string = originalPasteboard;
    });
}

[zuthan]

I solved this by creating a category for PTKView that provides a setCardNumber method and calls the textField:shouldChangeCharactersInRange:replacementString method like so:

PTKView+Programmable.h

@interface PTKView (Programmable)
    - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)replacementString;

    - (void)setCardNumber:(NSString *)cardNumber;
@end

PTKView+Programmable.m

@implementation PTKView (Programmable)
    - (void)setCardNumber:(NSString *)cardNumber {
        NSRange range = NSMakeRange(0, [self cardNumberField].text.length);
        [self textField:[self cardNumberField] shouldChangeCharactersInRange:range replacementString:cardNumber];
    }
@end

Since I'm using swift, I also had to add #import "PTKView+Programmable.h" to my Bridging-Header.h file.

Then I could simply call self.pkView.setCardNumber(cardNumber) in my PaymentViewController.

Since there are obvious use cases for setting the card fields programmatically (such as Card.io), please add this feature natively.